The position of a radio frequency (RF) tag as read by a tag interrogator may be anywhere within the footprint of the interrogator read antenna. Typically, the footprint width is wider than the desired position accuracy for determining the position of the RF tag with respect to the tag interrogator.
Prior solutions of which the inventor is aware employ a tag interrogator with read footprints of up to 1 meter or more in width. Further, signal processing may be used to estimate the location of the RF tag based on the received signal shape. RF tag position uncertainty, along with other data input, leads to the calculation of a safety distance in front of a vehicle having the tag interrogator in order to maintain a safe separation distance. As the position uncertainty increases so too does the safety separation distance with the result of requiring a larger separation distance than if the position were known. A larger separation distance results in lower vehicle throughput and ultimately less revenue, if applicable, for a vehicle operator.